Empty seas coming to a shore near you

12 07 2012

Last week I had the pleasure of entertaining some old friends and colleagues for a writing workshop in Adelaide (don’t worry – they all came from southern Australia locations, so no massive carbon footprints for overseas travel). I’m happy to report it was a productive (and epicurean) week, but that’s not really the point of today’s post.

One of those participants was long-time colleague, Dr. Rik Buckworth. Rik and I first met in Darwin back in the early 2000s when he was lead fisheries scientist for Northern Territory Fisheries; this collaboration and friendship blossomed into an ARC Linkage Project (with Dr. Mark Meekan of AIMS) on shark fisheries (see some of the scientific outputs from that here, here, here and here). Rik has since moved to CSIRO in Brisbane, but keeps a hand in NT fisheries’ affairs. Incidentally, Rik trained under one of the most well-known fisheries modellers in the world – Carl Walters – when he did his PhD at the University of British Columbia back in the early 1990s.

During our workshop, Rik pointed out a paper he had co-authored back in 2009 in Reviews in Fish Biology and Fisheries that had completely escaped my attention – it’s a frightening and apocalyptic view of the Australasian marine tropics that seems to confirm our predictions about northern Australia’s marine future. Just take a look at the following two figures from their paper (Elasmobranchs in southern Indonesian fisheries: the fisheries, the status of the stocks and management options): Read the rest of this entry »





Susceptibility of sharks, rays and chimaeras to global extinction

10 11 2009
tiger shark

© R. Harcourt

Quite some time ago my colleague and (now former) postdoctoral fellow, Iain Field, and I sat down to examine in gory detail the extent of the threat to global populations of sharks, rays and chimaeras (chondrichthyans). I don’t think we quite realised the mammoth task we had set ourselves. Several years and nearly a hundred pages later, we have finally achieved our goal.

Introducing the new paper in Advances in Marine Biology entitled Susceptibility of sharks, rays and chimaeras to global extinction by Iain Field, Mark Meekan, Rik Buckworth and Corey Bradshaw.

The paper covers the following topics:

  • Chondrichthyan Life Historyangel shark
  • Niche breadth
  • Age and growth
  • Reproduction and survival
  • Past and Present Threats
  • Fishing
  • Beach meshing
  • Habitat loss
  • Pollution and non-indigenous species
  • Chondrichthyan Extinction Risk
  • Drivers of threat risk in chondrichthyans and teleosts
  • Global distribution of threatened chondrichthyan taxa
  • Ecological, life history and human-relationship attributes
  • Threat risk analysis
  • Relative threat risk of chondrichthyans and teleosts
  • Implications of Chondrichthyan Species Loss on Ecosystem Structure, Function and Stability
  • Ecosystem roles of predators
  • Predator loss in the marine realm
  • Ecosystem roles of chondrichthyans
  • Synthesis and Knowledge Gaps
  • Role of fisheries in future chondrichthyan extinctions
  • Climate change
  • Extinction synergies
  • Research needs

common skateAs mentioned, quite a long analysis of the state of sharks worldwide. Bottom line? Well, as most of you might already know sharks aren’t doing too well worldwide, with around 52 % listed on the IUCN’s Red List of Threatened Species. This compares interestingly to bony fishes (teleosts) that, although having only 8 % of all species Red-Listed, are generally in higher-threat Red List categories. We found that body size (positively) and geographic range (negatively) correlated with threat risk in both groups, but Red-Listed bony fishes were still more likely to be categorised as threatened after controlling for these effects.

blue sharkIn some ways this sort of goes against the notion that sharks are inherently more extinction-prone than other fish – a common motherhood statement seen at the beginning of almost all papers dealing with shark threats. What it does say though is that because sharks are on average larger and less fecund than your average fish, they tend to bounce back from declines more slowly, so they are more susceptible to rapid environmental change than your average fish. Guess what? We’re changing the environment pretty rapidly.

We also determined the spatial distribution of threat, and found that Red-Listed species are clustered mainly in (1) south-eastern South America; (2) western Europe and the Mediterranean; (3) western Africa; (4) South China Sea and South East Asia and (5) south-eastern Australia.

shark market, Indonesia

© W. White

Now, what are the implications for the loss of these species? As I’ve blogged recently, the reduction in predators in general can be a bad thing for ecosystems, and sharks are probably some of the best examples of ecosystem structural engineers we know (i.e., eating herbivores; ‘controlling’ prey densities, etc.). So, we should be worried when sharks start to disappear. One thing we also discovered is that we still have a rudimentary understanding of how climate change will affect sharks, the ways in which they structure ecosystems, and how they respond to coastal development. Suffice it to say though that generally speaking, things are not rosy if you’re a shark.

We end off with a recommendation we’ve been promoting elsewhere – we should be managing populations using the minimum viable population (MVP) size concept. Making sure that there are a lot of large, well-connected populations around will be the best insurance against extinction.

CJA Bradshaw

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ResearchBlogging.orgI.C. Field, M.G. Meekan, R.C. Buckworth, & C.J.A. Bradshaw (2009). Susceptibility of Sharks, Rays and Chimaeras to Global Extinction Advances in Marine Biology, 56, 275-363 : 10.1016/S0065-2881(09)56004-X





Few people, many threats – Australia’s biodiversity shame

31 07 2009

bridled_nailtail_400I bang on a bit about human over-population and how it drives biodiversity extinctions. Yet, it isn’t always hordes of hungry humans descending on the hapless species of this planet  – Australia is a big place, but has few people (just over 20 million), yet it has one of the higher extinction rates in the world. Yes, most of the country is covered in some fairly hard-core desert and most people live in or near the areas containing the most species, but we have an appalling extinction record all the same.

A paper that came out recently in Conservation Biology and was covered a little in the media last week gives some telling figures for the Oceania region, and more importantly, explains that we have more than enough information now to implement sound, evidence-based policy to right the wrongs of the past and the present. Using IUCN Red List data, Michael Kingsford and colleagues (paper entitled Major conservation policy issues for biodiversity in Oceania), showed that of the 370 assessed species in Australia, 80 % of the threatened ones are listed because of habitat loss, 40 % from invasive species and 30 % from pollution. As we know well, it’s mainly habitat loss we have to control if we want to change things around for the better (see previous relevant posts here, here & here).

Kingsford and colleagues proceed to give a good set of policy recommendations for each of the drivers identified:

Habitat loss and degradation

  • Implement legislation, education, and community outreach to stop or reduce land clearing, mining, and unsustainable logging through education, incentives, and compensation for landowners that will encourage private conservation
  • Establish new protected areas for habitats that are absent or poorly represented
  • In threatened ecosystems (e.g., wetlands), establish large-scale restoration projects with local communities that incorporate conservation and connectivity
  • Establish transparent and evidence-based state of environment reporting on biodiversity and manage threats within and outside protected areas.
  • Protect free-flowing river systems (largely unregulated by dams, levees, and diversions) within the framework of the entire river basin and increase environmental flows on regulated rivers

Invasive species

  • Avoid deliberate introduction of exotic species, unless suitable analyses of benefits outweigh risk-weighted costs
  • Implement control of invasive species by assessing effectiveness of control programs and determining invasion potential
  • Establish regulations and enforcement for exchange or treatment of ocean ballast and regularly implement antifouling procedures

Climate change

  • Reduce global greenhouse gas emissions
  • Identify, assess, and protect important climate refugia
  • Ameliorate the impacts of climate change through strategic management of other threatening processes
  • Develop strategic plans for priority translocations and implement when needed

Overexploitation

  • Implement restrictions on harvest of overexploited species to maintain sustainability
  • Implement an ecosystem-based approach for fisheries, based on scientific data, that includes zoning the ocean; banning destructive fishing; adopting precautionary fishing principles that include size limits, quotas, and regulation with sufficient resources based on scientific assessments of stocks and; reducing bycatch through regulation and education
  • Implement international mechanisms to increase sustainability of fisheries by supporting international treaties for fisheries protection in the high seas; avoiding perverse subsidies and improve labelling of sustainable fisheries; and licensing exports of aquarium fish
  • Control unsustainable illegal logging and wildlife harvesting through local incentives and cessation of international trade

Pollution

  • Decrease pollution through incentives and education; reduce and improve treatment of domestic, industrial, and agriculture waste; and rehabilitate polluted areas
  • Strengthen government regulations to stop generation of toxic material from mining efforts that affects freshwater and marine environments
  • Establish legislation and regulations and financial bonds (international) to reinforce polluter-pays principles
  • Establish regulations, education programs, clean ups, labelling, and use of biodegradable packaging to reduce discarded fishing gear and plastics

Disease

  • Establish early-detection programs for pathological diseases and biosecurity controls to reduce translocation
  • Identify causes, risk-assessment methods, and preventative methods for diseases
  • Establish remote communities of organisms (captive) not exposed to disease in severe outbreaks

Implementation

  • Establish regional population policies based on ecologically sustainable human population levels and consumption
  • Ensure that all developments affecting the environment are adequately analysed for impacts over the long term
  • Promote economic and societal benefits from conservation through education
  • Determine biodiversity status and trends with indicators that diagnose and manage declines
  • Invest in taxonomic understanding and provision of resources (scientific and conservation) to increase capacity for conservation
  • Increase the capacity of government conservation agencies
  • Focus efforts of nongovernmental organisations on small island states on building indigenous capacity for conservation
  • Base conservation on risk assessment and decision support
  • Establish the effectiveness of conservation instruments (national and international) and their implementation

A very good set of recommendations that I hope we can continue to develop within our governments.

CJA Bradshaw

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Interview with… ConservationBytes

16 07 2009

CBlogoA few months ago I was asked to do an online interview about ConservationBytes at The Reef Tank. I previously made mention of the interview (see post), but I think it’s time I reproduce it here.

The effects of pollution, carbon build up in the ocean, extinction, loss of coral reefs, over-fishing, and global warming is increasingly becoming more detrimental to our marine life and marine world.

Fortunately our marine ecosystems have Corey Bradshaw on their side. As a conservation ecologist, Corey studies these ecosystems with a passion, trying to understands the interactions between plants and animals that make up these ecosystems as well as what human activity is doing to them.

He has realised long ago that conservation and awareness is crucial to the survival of these living things and carries on the long tradition of studying and trying to understand these ecosystems at the School of Earth & Environmental Sciences at the University of Adelaide in South Australia.

He also avidly blogs about these pertinent issues at ConservationBytes.com, because he felt a need that these marine conservation issues needed to be heard. And he was more then right.

We were lucky enough to grab some time with Corey Bradshaw and he was kind enough to answer some important marine conservation questions, which are important in our desire: to make the marine world a better place.

What is your background in science and conservation?

I have a rather eclectic background in this area. I originally started my university education in general ecology, with a focus on plant ecology in particular (this was the strength of my undergraduate institution). There was no real emphasis on conservation per se until I started my postgraduate studies, although even then I was more interested in the empirical side of theoretical ecology than on conservation itself. It was more or less a gradual process that as I realised just how much we as a species have changed the planet in our (relatively) short time here, I became more and more dedicated to quantifying the links between species loss and how it affects human well-being.

After completing my MSc, PhD and first postdoctoral fellowship in New Zealand and Australia, I had the good fortune to work alongside a few excellent conservation ecologists specialising in extinction dynamics. This is where my mathematical bent and conservation interests really took off and eventually set the stage for most of my research today.

Your blog is ConservationBytes.com. Why the urge to start a blog on conservation only?

It may seem odd that I resisted blogging for many years because I thought it was a colossal time-waster that would take me away from my main scientific research. However, several things convinced me of its need and utility. First, it’s a wonderful vehicle to engage non-scientists about the research one does – let’s face it, most people don’t read scientific journals. Second, it’s interactive; people can ask questions or comment directly online. Third, it overcomes the strict language and technical rigour of most scientific publications and gets to the heart of the issue (it also allows me to express some opinions and speculations that are otherwise forbidden in scientific writing). Fourth, I realised there was a real lack of understanding about basic conservation science among the populace, so providing a vehicle for conservation science dissemination online appeared to be a good idea – there simply wasn’t anything like it when I started only a year ago. Finally, an effective, policy-changing scientist must advertise his/her research through the popular media to be recognised, so it obviously has career benefits.

Tell me about the conservation topics you cover?

ConservationBytes.com covers pretty much any topic that conforms to at least one of the following criteria:

  • It concerns research (previous, ongoing, planned) that is designed to improve the fate of biodiversity, whether locally, regionally or internationally

  • It concerns policy studies, actions or ideas that will have positive bearing on biodiversity conservation

  • It concerns demonstrations of the role biodiversity plays in providing humans with essential ecosystem services

I even have a section I call ‘Toothless’ that highlights ineffective conservation research or policy. Other areas include: exposés of well-known conservation scientists, a collection of links to conservation science journals, and my personal information (publications, CV, media attention).

What is your take on marine conservation? What does marine conservation include?

Given that I have worked in both marine and terrestrial realms from the tropics to the Antarctic, I really see little distinction in terms of conservation. True, the marine realm probably presents more challenges to conservation in some respects because it’s generally much more difficult and expensive to collect meaningful data, and it’s more difficult to control or mitigate people’s behaviour (especially in international waters), but the ecological patterns are the same (although I admit they may operate over different spatial and temporal scales).

Current ‘hot’ topics in marine conservation include the global degradation and loss of coral reef ecosystems (and what to do about it), terrestrial run-off of pollutants and nutrients affecting marine communities, over-fishing and better fishing management strategies, the design of effective marine protected areas, the socio-economic implications of moving people away from direct exploitation to behaviours and economic activities that promote longer-term biological community stability and resilience, and of course, how climate change (via acidification, hypercapnia, temperature change, storm intensification, seal level rise and modified current structure) might exacerbate the systems that are already stressed by the aforementioned problems.

Have you done any work, research in the area of marine conservation?

Yes, quite a bit. Some salient areas include

  • The grey nurse shark Carcharias taurus was the world’s first shark species to receive legislative protection when the east Australian population was listed under the 1984 New South Wales Fisheries Management Act. It has since been listed as globally Vulnerable by the IUCN in 1996 and the east Australian population was declared Critically Endangered in 2003. Previously, we constructed deterministic, density-independent PVA models for the east Australian population that suggested dire prospects for its long-term persistence without direct and immediate intervention. However, deterministic models might be overly optimistic because they do not incorporate stochastic fluctuations that can drive small populations extinct, whereas failing to account for density feedback can predict overly pessimistic. We recently completed a study demonstrating that the most effective measure to reduce extinction risk was to legislate the mandatory use of offset circle hooks in both recreational and commercial fisheries. The increase in dedicated marine reserves and shift from bather protection nets to drumlines had much lower effectiveness.

  • The global extent of illegal, unreported and unregulated (IUU) fishing is valued from US$10-23.5 billion per year, representing between 11 and 26 million tonnes of fish killed annually beyond legal commercial catches. In northern Australia, IUU fishing has advanced as a ‘protein-mining’ wave starting in the South China Sea in the 1970s and now penetrates consistently into the nation’s Exclusive Economic Zone. We have documented the extent of this wave and the implications for higher-order predators such as sharks, demonstrating that IUU fishing has already depleted large predators in Australian territorial waters. Given the negative relationship between IUU fishing takes and governance quality, we propose that deterring invading fishers will need substantially greater investment in border protection, and international accords to improve governance in neighbouring nations, if the tide of extinction is to be effectively mitigated.

  • Determining the extinction risk of the world’s shark and ray species – some work I’ve done recently with colleagues is to examine the patterns of shark biodiversity globally and determine which groups are most at risk of extinction. Not a surprise, but it turns out that the largest species of shark that reproduce the slowest are the most endangered (including all those bitey ones that frighten people).

  • Finally, I’m doing a lot of work now examining how the structure of coral reefs affects fish biodiversity patterns and long-term resilience. It turns out that basic biogeographic predictors (e.g., reef size and relative isolation from other reefs) really do dictate how temporally stable fish populations remain. And as we know, the more variable a population in time and space, the more likely it will go extinct (on average). The practical implication is that we can identify those coral reefs most likely to maintain their fish communities simply by measuring their size and position.

You’re from Australia, correct? What kind of marine conservation is going on there?

I’m originally from Canada, but I’ve spent most of my adult life in Australia (mostly in Tasmania, the Northern Territory, and now, Adelaide in South Australia). I did my PhD in the deep south of New Zealand (Otago University, Dunedin). In Australia, all the aforementioned ‘hot’ areas of marine conservation are in full swing, with greater and greater emphasis on climate change research. I think this aspect is pre-occupying most serious marine ecologists in Australia these days. For example, the southeast of Australia has already experienced some of the fastest warming in the Southern Hemisphere, with massive regional shifts in many species of fish, invertebrates, macroalgae and plankton.

What’s your take on ocean acidification? Do you think people need to be aware of this issue?

I used to believe ocean acidification was THE principal marine conservation issue facing us today, but now I think it’s just another stressor in a cornucopia of stressors. The main issue here is that we still understand so little of its implications for marine biodiversity. Sure, you lower the pH and up the partial CO2 (pCO2) of seawater, and many organisms don’t do so well (in terms of survival, reproduction and growth). However, it’s considerably more complex than this. pH and pCO2 vary substantially in space and time, and we have yet to quantify these patterns or how they are changing for most of the marine realm. Therefore, it’s difficult to simulate ‘real’ and future conditions in the lab.

Another issue is that temperature is changing must faster and so far exposure experiments indicate that it generally has a much more pronounced effect on marine organisms than acidification per se. However, like many climate change issues, a so-called ‘tipping point’ could be just around the corner that makes many marine communities collapse. It’s a frightening prospect, but one that needs a lot more dedicated research.

Can a person own an aquarium and still be considered a marine conservationist in your opinion?

Of course, provided one is cognisant of several important issues. First, most aquarists rely on the importation of non-native species. Lack of vigilance and carelessness has resulted in a suite of alien species being released into naïve ecosystems, resulting in the extinction or reduction of many native fish and invertebrates. Another issue is the transport cost – think how much carbon you are emitting by flying that tropical clownfish to your local pet shop in Norway. Third, do you know from which populations your displayed fish come? Were they harvested sustainably, or were they the last individuals plucked from a dying reef? A good knowledge of an animal’s origin is essential for the responsible aquarist. In my view one should play it safe. I think having aquaria filled with local species that are easily acquired, don’t cost the Earth to transport and pose no risk to native ecosystems is the most responsible way to go. You can also be a lot more certain of sustainable harvest if you live close by the source.

What is your take on climate change and its effect on marine life? Is being aware and educated on this particular topic and how it affects the marine world make someone a marine conservationist?

Awareness is only the first and most basic step. I’d say most of the world is ‘aware’ to some extent. It’s really the change in human behaviour that’s required before we make any true leaps forward. Some of the issues described above get to the heart of behavioural change. To use an analogy, it’s not enough to recognise that you’re an alcoholic, you have to stop drinking too to prevent the damage.

What can we do to raise awareness of the importance of marine conservation and conservation in general?

My personal take on this, and it applies to ALL biodiversity conservation (i.e., not just marine) is that people won’t take it seriously until they see how its loss affects their lives negatively. For example, let’s say we lose all commercially exploitable fish – not having access to delicious and healthy fish protein will mean people change the way fishing is done; that is, they’ll try to force fishers to fish sustainably and consumers to demand responsibly. The same can be said for more esoteric ecosystem services like carbon sequestration, oxygen production, water purification, pollination, waste detoxification, etc. if, and only if, we understand the economic and health benefits of keeping ecosystems intact. We need more research that makes the biodiversity-human benefit link so that people ultimately get the message. Destroying biodiversity means destroying yourself.

As I said before, awareness is only the first step.





Protein mining the world’s oceans

31 03 2009

Last month David Agnew and colleagues published a paper in PLoS One examining the global extent of illegal, unreported and unregulated (IUU) fishing (Estimating the worldwide extent of illegal fishing), estimating its value from US$10-23.5 billion and representing between 11 and 26 million tonnes of fish annually. The value is roughly the same as that lost from illegal logging each year. Wow.

Of perhaps most interest is that Agnew and colleagues found evidence for a negative relationship between IUU fishing as a proportion of total catch and an international (World Bank) governance quality index. This suggests that improving governance and eradicating corruption may be the best way to curtail the extent of the illegal harvest.

We have just published a paper online in Fish and Fisheries about the extent and impact of IUU fishing in northern Australia. Entitled Protein mining the world’s oceans: Australasia as an example of illegal expansion-and-displacement fishing, the paper by Iain Field and colleagues advocates a multi-lateral response to a problem that has grown out of control in recent decades.

IUU fishing is devastating delicate ecosystems and fish breeding grounds in waters to Australia’s north, and can no longer be managed effectively by individual nations. The problem now requires an urgent regional solution if food security into the future is to be maintained.

The paper is the first big-picture account of the problem from Australia’s perspective. Although there had been a decline in IUU fishing in Australian waters over the past two years, possibly linked to large Australian government expenditure on enforcement and rising fuel prices, the forces driving illegal fishing have not gone away and are likely to resurface in our waters.

We expect that the small-scale illegal fishers will be back to prey on other species such as snapper, trochus and trepang as soon as it is economically viable for them to do so. To date, these IUU fishers have focused mostly on high-value sharks mainly for the fin trade, to the extent that the abundance of some shark species has dropped precipitously. IUU fishing, which has devastated fish resources and their associated ecosystems throughout Southeast Asian waters, is driven by deep economic and societal forces. For example, the Asian economic crisis in the late 1990s drove a large number of people out of cities and into illegal fishing.

It is not enough to maintain just a national response as the problem crosses national maritime zones, and it poses one of the biggest threats known to marine ecosystems throughout the region. These IUU fishers are mining protein, and there is no suggestion of sustainability or factoring in fish breeding or ecosystem protection into the equation. They just come into a fishing area and strip-mine it, leaving it bare.

Illegal fishing in Australian waters started increasing steeply about 10 years ago, largely because of over-exploitation of waters farther north, peaking in 2005-06 then falling away just as steeply. There are three factors behind the recent downturn: Australian government enforcement measures estimated to have cost at least AU$240 million since 2006; the high price of fuel for the fishing boats; and, most importantly, the fact that the high-value species may have been fished out and are now economically and ecologically extinct.

The $240 million has funded surveillance, apprehension, transportation, processing and accommodation of the several thousand illegal foreign fishermen detained each year since 2006. These activities have been successful, but it is doubtful whether they can hold back the IUU tide indefinitely – the benefits to the illegal fishers of their activities far outweigh the penalties if caught.

With increasing human populations in the region, the pressure to fish illegally is likely to increase. Regional responses are required to deter and monitor the illegal over-exploitation of fisheries resources, which is critical to secure ecosystem stability as climate change and other destructive human activities threaten food security.

CJA Bradshaw (with IC Field, MG Meekan and RC Buckworth)

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